Allocating Swap Space for UFS-Based Systems

In addition to preceding general guidelines, consider allocating swap
space or disk space for a UFS-based system for the following:

A dedicated dump device.

The /var/crash directory. The default
system crash dump content is kernel memory pages only and the dump is compressed
before it is written. Consider sizing this directory to the size of the dump
device unless you attend to keep several system crash dumps.

Determine whether large applications (such as compilers) will
be using the /tmp directory. Then, allocate additional
swap space to be used by TMPFS. For information about TMPFS, see Swap Space and the TMPFS File System.